Achromatic lens array

ABSTRACT

A luminescence detection system may include an excitation light source, a single element achromat, and a detector. The single element achromat may be configured to regulate the excitation light from the light source and direct the regulated light to a target, and the detector may be configured to detect luminescence generated by the target. The single element achromat may be configured to regulate the emission light from the target and direct the regulated light to a detector, and the excitation light source may be configured to direct the excitation light to the target. The single element achromat may be configured to regulate both the excitation light from the light source and the emission light from the target and direct the regulated light to, respectively, the target and a detector.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 11/225,968, filed Sep. 13, 2005, which is acontinuation-in-part of U.S. patent application Ser. No. 11/096,341,filed Mar. 31, 2005, now U.S. Pat. No. 7,407,798, and patent applicationSer. No. 10/146,066, filed May 16, 2002, now U.S. Pat. No. 6,982,166,which applications are herein incorporated herein by reference in theirits entirety.

FIELD

The present invention relates to an optical system for focusing lightonto or collecting light from one or more samples in a system forbiological testing. In one aspect, the invention relates to a lensassembly having the functions of collimating and focusing light onto oneor more samples integrated into the lens assembly. In another aspect,the invention relates to a lens assembly having the functions ofcollimating and focusing light from one or more samples integrated intothe lens assembly.

BACKGROUND

Biological testing has become an important tool in detecting andmonitoring diseases. In the biological testing field, thermal cycling isused to amplify nucleic acids by, for example, performing PCR and otherreactions. PCR in particular has become a valuable research tool withapplications such as cloning, analysis of genetic expression, DNAsequencing, and drug discovery.

Recent developments in the field have spurred growth in the number oftests that are performed. One method for increasing the throughput ofsuch biological testing is to provide real-time detection capabilityduring thermal cycling. Real-time detection increases the efficiency ofthe biological testing because the characteristics of the samples can bedetected while the sample well tray remains positioned in the thermalcycling device.

In a real-time detection system, testing may be performed on multiplesamples during a cycle of the testing device. With this type of system,light may be emitted from a light source to be reflected off of thebiological sample(s) and ultimately may be detected or collected by alight detecting device such as a camera or CCD, for example. To assistwith focusing the light into and directing the light out of the samplestoward detecting device, one or more lenses may be provided.

One of the drawbacks of conventional devices utilizing lens assembliesin conjunction with multiple sample testing devices is the complexity ofthe lens(es). It may often be desirable to have a lens for collimatinglight so that it may be properly aligned with a row or column of samplewells in a sample well tray. To further enhance the testing process, anadditional lens assembly may be provided for focusing light moreprecisely within each of the sample wells. These focusing lensassemblies often may comprise a plurality of non-integral components,resulting in a bulky structure.

Another drawback of conventional devices is chromatic aberration. Someconventional instruments comprise light sources emitting light havingone or more excitation wavelengths and samples emitting light at one ormore emission wavelengths. Optical systems direct excitation light fromsources to samples and/or from samples to detectors. When these systemsare not corrected for chromatic aberration, vignetting and systemthroughput become functions of wavelength. When the systems arecorrected for chromatic aberration, wavelength-dependent responsevariations may be substantially reduced.

Some conventional sample testing devices utilize two or more bonded lenselements that serve to collect and focus light. Such devices may have aless bulky structure, but the use of bonded elements of materials withdifferent dispersions may result in spherical and/or chromaticaberration of the light. Some conventional refractive achromats maycorrect both spherical and chromatic aberrations, but typically requirethe use of glass and more costly fabrication.

Accordingly, it may be desirable to provide a sample testing devicehaving a diffractive/refractive hybrid lens that reduces sphericaland/or chromatic aberration of light. It may be desirable to manufacturethe diffractive/refractive hybrid from a polymer with a single-stepprocess, thus saving material and manufacturing costs.

SUMMARY

In accordance with various aspects of the invention, a luminescencedetection system may comprise a light source configured to illuminate atarget, a detector configured to detect target luminescence, and asingle element achromat configured to regulate at least one of lightfrom the light source and luminescence from the target.

In accordance with various aspects, a lens assembly may comprise asingle element achromat configured to regulate at least one of lightilluminating a target and target luminescence.

According to various aspects of the invention, the single elementachromat may comprise a single surface comprising at least onerefractive feature and at least one diffractive feature. The at leastone diffractive feature may be configured to minimize chromaticaberration of at least one of the light from the light source and theluminescence from the target.

According to some aspects, the at least one refractive feature maycomprise a spherical feature or an aspheric feature configured tominimize spherical aberration of at least one of the light from thelight source and the luminescence from the target.

In accordance with various aspects, the single element achromat maycomprise a refractive surface and a diffractive surface. The diffractivesurface may be configured to minimize chromatic aberration of at leastone of the light from the light source and the luminescence from thetarget.

In accordance with some aspects, the refractive surface may comprise aspherical surface or an aspheric refractive surface configured tominimize spherical aberration of at least one of the light from thelight source and the luminescence from the target.

According to various aspects, a method of luminescence detection maycomprise Illuminating a sample, detecting sample luminescence, andpassing at least one of light illuminating the sample and the sampleluminescence through a single element achromat.

In accordance with some aspects, at least one of light illuminating thesample and the sample luminescence may be passed through a singlesurface comprising at least one refractive feature and at least onediffractive feature. The diffractive feature may be configured tominimize chromatic aberration of at least one of the illuminating lightand the target luminescence.

In accordance with various aspects, at least one of light illuminatingthe sample and the sample luminescence may be passed through arefractive surface and a diffractive surface. The diffractive surfacemay be configured to minimize chromatic aberration of at least one ofthe illuminating light and the target luminescence.

According to various aspects, an optical detection system for a thermalcycling device may comprise at least one light source configured toilluminate at least one of a plurality of samples, a light detectiondevice configured to detect luminescence from at least one of aplurality of biological samples, and a lens. The lens may have first andsecond surfaces, wherein the second surface faces a direction oppositeto that of the first surface. The first surface may be configured tocollimate light, and the second surface may comprise a matrix of lenses.The matrix may comprise a plurality of focusing lens portions configuredto direct light into each of the plurality of biological samples. Eachfocusing lens portion may comprise at least one refractive feature andat least one diffractive feature. The diffractive feature may beconfigured to minimize chromatic aberration of at least one of lightfrom the light source and the luminescence from the target.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate at least one exemplary embodimentof the invention. In the drawings,

FIG. 1 is a partial section view of a biological testing deviceaccording to an exemplary embodiment of the invention;

FIG. 2 is a plan view of a first side of a single-piece lens depicted inFIG. 1;

FIG. 3 is a plan view of a second side of the single-piece lens of FIG.2;

FIG. 4 is a section view of the single-piece lens of FIG. 2;

FIG. 5 is a close-up view of the circled portion of FIG. 4;

FIG. 6 is a section view of a exemplary single-piece lens in accordancewith aspects of the invention; and

FIG. 7 is a partial section of the lens of FIG. 1 in combination with amicrocard sample tray.

DESCRIPTION OF THE VARIOUS EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts, and thesame reference numbers with alphabetical suffixes or numerical prefixesare used to refer to similar parts.

In accordance with certain embodiments, a biological testing device isprovided. In one aspect, the biological testing device can performnucleic acid amplification. In certain embodiments, the biologicaltesting device includes a light source, a light detection device, and alens. In various embodiments, the biological testing device can alsoinclude a sample block, a heated cover, a sample well tray, a seal forcovering openings of the sample wells in the sample well tray, a lightrefractor, a light reflector, and/or a filter, among other components.

In FIG. 1, a generally schematic view is shown that is representative ofa biological testing device 10 according to an embodiment of theinvention. For example, testing device 10 can be any type of deviceconfigured to perform nucleic acid amplification. One common method ofperforming nucleic acid amplification of biological samples ispolymerase chain reaction (PCR). Various PCR methods are known in theart, as described in, for example, U.S. Pat. Nos. 5,928,907 and6,015,674 to Woudenberg et al., the complete disclosures of which arehereby incorporated by reference for any purpose. Other methods ofnucleic acid amplification include, for example, ligase chain reaction,oligonucleotide ligations assay, and hybridization assay. These andother methods are described in greater detail in U.S. Pat. Nos.5,928,907 and 6,015,674.

In one embodiment, the thermal cycling device performs real-timedetection of the nucleic acid amplification of the samples duringthermal cycling. Real-time detection systems are known in the art, asdescribed in greater detail in, for example, U.S. Pat. Nos. 5,928,907and 6,015,674 to Woudenberg et al., incorporated herein above. Duringreal-time detection, various characteristics of the samples are detectedduring the thermal cycling in a manner known in the art. Real-timedetection permits more accurate and efficient detection and monitoringof the samples during the nucleic acid amplification.

In accordance with various embodiments, the testing device may include alight or radiation source. As embodied herein and shown in FIG. 1, thetesting device includes a light source 16 for directing light onto aplurality of biological samples. The biological samples can bepositioned in any type of known sample-receiving member. In theembodiment shown in FIG. 1, the samples 60 are located in sample wells44 of a sample well tray 40. Light source 16 can be any conventionaltype of light source suitable for biological testing, such as a quartzbulb, a laser, (e.g. an argon ion laser), or an LED, for example. Lightemitted from light source 16 can be aimed directly toward sample welltray 40, or light source 16 could be aimed at a beam splitter (notshown) that then can redirect at least a portion of the light towardsample well tray 40.

In accordance with various embodiments, biological testing device 10includes an optical detection system. As embodied herein and shown inFIG. 1, an optical detection device 12 is positioned above the samplewell tray 40. The optical detection system 12 is configured to detectand monitor the characteristics of the samples in the sample well tray40 during the testing. Suitable structures and methods for the opticaldetection device 12 are well known in the art. The optical detectiondevice can use any known structure or method. In one example, theoptical detection device could include a CCD camera, in a manner knownin the art. Likewise, the optical detection device can include any othertype suitable for use with the thermal cycling device of the presentinvention.

In certain embodiments, a filter 14 can be provided for filtering thelight reflected from the sample and allowing only a predetermined rangeof light waves to enter the optical detection device 12. Other elementsknown to be included in detecting devices can be included in testingdevice 10, such as a prism, a mirror, or a spectrograph, among others.

In accordance with various embodiments, a seal may be provided for thesample well tray. In one embodiment shown in FIG. 1, sample well tray 40is covered by a film 42 for sealing the various sample wells 44 and foraiding in minimizing contamination of biological samples 60. Film 42 canbe provided with an adhesive on the side facing sample well tray 40 tosecure it in place. The film can be made out of any known materialsuitable for use with a sample well tray.

In accordance with various embodiments, the biological testing devicecan include a heated cover. In the embodiment shown in FIG. 1, a cover30 is located above film 42. As shown in FIG. 1, cover 30 includes a lip32 around its perimeter. Lip 32 can be continuous or it can bediscontinuous. Lip 32 is raised above surface 34 onto which a lens array20 may be placed. In combination, lip 32 and surface 34 can serve tolocate and hold lens array 20 in a desired position in relation to cover30. Cover 30 also includes a plurality of openings 36, with each openingbeing positioned over one of the sample wells 44 to allow light to passthrough cover 30 and into biological samples 60 in the sample wells 44.As depicted in FIG. 1, openings 36 can taper from an upper edge 36 a toa lower edge 36 b. In certain embodiments, cover 30 can be heated toaugment heating of biological samples 60 provided by a sample block 70.Acting as a heated cover, cover 30 can also serve a function to reducecondensation within the system.

In the embodiment shown, cover 30 rests on film 42, which in turn restsor is adhered to sample well tray 40. Sample well tray 40 can be anymember utilized in biological testing to hold one or more samples. Inthe embodiment shown in FIG. 1, sample well tray 40 includes a pluralityof sample wells 44 for holding biological samples 60. Sample wells 44each comprise an upper portion 44 a that has a substantially cylindricalshape and a tapered lower portion 44 b that ends in a rounded bottomportion 44 c. It is well understood that the sample wells may have anyknown size, shape, or configuration.

Biological testing device 10 can be configured for use with any type ofsample well tray, including, for example, 96-well sample well trays,384-well sample trays, and microcard sample trays. The size and shape ofthese sample well trays are well known in the art. Examples of 96-wellsample well trays suitable for use in the present invention aredescribed in WO00/25922 to Moring et al., the complete disclosure ofwhich is hereby incorporated by reference for any purpose. Examples ofsample well trays of the microcard type suitable for use in the presentinvention are described in WO01/28684 to Frye et al., the completedisclosure of which is hereby incorporated by reference for any purpose,WO97/36681 to Woudenberg et al., the complete disclosure of which ishereby incorporated by reference for any purpose, U.S. Pat. No.6,514,750, assigned to the assignee of the present invention, thecomplete disclosure of which is hereby incorporated by reference for anypurpose, and U.S. application Ser. No. 09/977,225, filed Oct. 16, 2001,assigned to the assignee of the present application, the completedisclosure of which is hereby incorporated by reference for any purpose.Sample well trays having any number of sample wells and sample wellsizes may also be used with the thermal cycling device of the presentinvention. In the example shown in the figures, the volume of the samplewells can vary anywhere from about 0.01 μl to thousands of microliters(μl), with a volume between 10 to 500 μl being typical.

In accordance with various embodiments, the testing device can include asample block. As embodied herein and shown in FIG. 1, sample well tray40 can be configured to mount onto sample block 70. Sample block 70 canbe any sample block known in the art that is used to receive a samplewell tray and provide heating and/or cooling of biological samples 60.Sample block 70 can be machined or cast of a material suitable forconducting heat to sample tray 40 and can include a plurality of samplewell openings 72 equal in number to a number of sample wells 44 ofsample tray 40.

As mentioned above, lens array 20 can rest on, or be otherwise adjacentto, cover 30 and can perform the function of both focusing andcollimating light emitted from and/or directed to samples 60. Accordingto various aspects, lens array 20 can comprise a single element havingat least two surfaces: a first surface 22 facing detection device 12 anda second surface 24 facing sample well tray 40. As used herein,“surface” is intended to broadly define a generally planar externalportion of the lens that may include a plurality of sub-surfaces formedinto the surface with the various sub-surfaces providing the desiredoverall lens characteristics.

According to various aspects, first surface 22 can comprise a Fresnellens for collimating light, and second surface 24 can include a matrix25 having a plurality of focusing lens portions or segments 26 equal tothe number of sample wells 44. Each focusing lens portion or segment 26is defined as the portion of surface 24 configured to focus light intoan individual sample 60.

FIG. 2 shows the configuration of first surface 22. This configurationcan be, for example, a Fresnel lens of the type manufactured by theFresnel Technologies of Fort Worth Tex. There are at least two basictypes of Fresnel lenses. The first has a constant pitch with increaseddepth toward the outer edges, and the second has a uniform depth. Eitherconfiguration could be used, but the uniform depth Fresnel lens isdepicted in the embodiment shown in FIGS. 1-4.

Each of the lens segments 26, shown in more detail in FIGS. 3 and 4, cancomprise a hybrid achromatic lens such as, for example, a lens havingrefractive and diffractive features. According to various embodiments,each refractive element of the hybrid lens can comprise a spherical oraspherical surface having diffractive structures thereon.

In an exemplary operation, as can be seen in FIGS. 1-4, light emittedfrom light source 16 contacts first surface 22 of lens array 20. In theembodiment shown, first surface 22 can collimate light beams 18 so thatthe light is directed toward each of the rows or columns of sample wells44 of sample well tray 40. Light beams 18 then pass through to a secondsurface 24 of lens array 20 which has formed on its surface a matrix 25of focusing lenses (or focusing lens segments) 26 as shown in FIG. 3 forfocusing light into each of biological samples 60 located in samplewells 44. Light beams 18 may have one or more wavelength selected tocreate luminescence by certain components of the samples 60 that a userwishes to identify. The wavelengths selected depend on the emission andabsorption properties of the desired components. The luminescence fromthe samples 60 can pass through lens array 20 in a reverse direction ofthe light emitted from the light source 16. Lens array 20 can collectthe reflected light and direct it toward detecting device 12.

It should be appreciated that according to various aspects, lens array20 may regulate (e.g., collect, collimate, focus, and/or direct) lightbeams passing from the light source 16 toward the samples 60 and/orsample luminescence passing toward the detector 12.

As seen in FIG. 5 in a close-up view of light passing through one of thefocusing lens segments 26, light beams 18 pass through first side oflens 22 and are collimated. As beams 18 pass through the second surface24, they are focused toward the desired sample location. As depicted,each lens segment 26 comprises a hybrid refractive/diffractive lens toaccomplish the focusing, while reducing chromatic aberration. If thelens segments 26 have an aspheric surface, the lens array 20 may alsoreduce spherical aberration.

In the embodiment shown in FIGS. 1-4, lens array 20 integrates both thecollimating function of side 22 and the focusing function of side 24into a single, monolithic, lens array. First, as can be seen in FIG. 4,by forming the focusing lens segments 26 into the second surface 24 oflens array 20, focusing lens segment 26 may occupy a substantial portionof the area over its associated sample well 44. This expanded lensallows for a maximum amount of light to pass into each of the samples60. In addition, focusing lens segments 26, being formed into the secondsurface 24, are fixed in relation to each other, thus minimizing thepotential for movement between respective focusing lens segments.

Also, by integrating Fresnel lens side 22 and focusing lens side 24 intoopposing surfaces of lens array 20, the potential for misalignment maybe reduced or even eliminated between the collimating and focusingfunctions. Because Fresnel lens side 22 and focusing lens side 24 oflens array 20 are fixed in relation to each other, a correct alignmentwith respect to each other may be desirably maintained.

As described herein and shown in FIG. 1, heated cover 30 may alsoprovide a mounting surface 34 for lens array 20 that may assist inmaintaining a proper alignment between lens array 20 and sample welltray 40. Further enhancing this alignment, lens array 20 can optionallybe fastened to heated cover 30 by any fastening means known in the art(e.g., a mechanical device such as clips, clamps, screws, adhesives,etc.) so as to further reduce movement and alignment problems betweenlens array 20 and heated cover 30.

In another aspect, lens array 20 may be configured so that one or moreof lens segments 26 may provide light of a different intensity ascompared to another of lens segments 26. According to some aspects,light source 16 may be a type of light source that emits light offocused intensity that is concentrated at a central area of lens array20. As one moves toward the periphery of the lens assembly, the lightemitted by light source 16 may be diminished. To compensate for this,one or more of focusing lens segments 26 may be configured in such a wayas to substantially equalize the intensity of the light that is focusedinto each of the samples 60.

In certain embodiments, for example, the focusing lens segments 26located near the center of lens array 20 could be molded in a fashionwhereby the optics of the individual focusing lens segments could bevaried so that they allow less light to pass through than focusing lenssegments located at a periphery of lens array 20. For example, accordingto one aspect, the aperture of the focusing lens segments 26 may belimited. Any or all of focusing lens segments 26 could be altered in asimilar fashion to correspond to varying intensities of light directedonto the grid of lens array 20. This could also be accomplished, forexample, by masking a portion of selected focusing lens segments toreduce the amount of light that passes through them. The term“mask(ing)” as used herein is intended to mean reducing or completelyinhibiting the light transmission capability of at least a portion ofeach of the focusing lens(es). This could be accomplished by applying acoating, for example paint, that would occlude at least a portion of thefocusing lens segment. Masking could also include applying an adhesivematerial such as tape to a portion of the focusing lens segment forreducing the amount of light that passes through the lens. This maskingcould be done in various amounts throughout the lens matrix to achievethe desired intensity of light into each of the samples 60. For example,the masking may be performed cutting holes in a thin aluminum sheet, andthen anodizing the sheet or painting it black.

Referring now to FIG. 6, in accordance with various aspects, thebiological detection system 10 disclosed herein can comprise a hybridachromatic lens 620 rather than lens array 20 described above. As shown,lens 620 can include a conventional refractive element on a firstsurface 622 and a diffractive element on an opposite second surface 624.Thus, lens 620 may be desirable in a detection system that does notrequire a Fresnel lens feature or in a detection system that includes aFresnel lens element separate from the hybrid achromatic lens 620. Theconventional refractive first surface 622 can comprise a sphericalsurface or an aspherical surface. Operationally, lens 620 functionssimilarly to the second surface 24 of lens array 20 in that light beamspassing through the lens 620 are focused toward the desired samplelocation and chromatic aberrations can be minimized. An aspherical firstsurface 622 can also minimize spherical aberrations.

Lens array 20, 620 may be made by any suitable method. For example, itis contemplated that lens array 20, 620 could be manufactured byinjection or compression molding. Lens array 20, 620 could be made of anon-fluorescing clear polycarbonate, for example. Testing devices usinga heated cover, such as heated cover 30, often operate at temperaturesapproaching or even exceeding 80° C. For such high-temperature devices,a material such as Lexan is suitable for lens array 20. Devicesoperating at lower temperatures, for example at or near 60° C., mayinclude a lens made of any number of materials such as acrylics,styrenes, polyethylenes, polycarbonates, polypropylenes, or any othertransparent plastic that may be suitable. Other materials, such asglass, may also be contemplated that would provide the same or similarcharacteristics as the ones included herein.

Although lens array 20 is shown in a 12×8 grid configuration comprising96 focusing lens segments, it is to be understood that this lensconfiguration could be modified into substantially any configuration tocorrespond with various sample well tray configurations or shapes. Forexample, lens array 20, 620 could have 4, 8, 12, 24, 96, 384, or 1536focusing lens segments. Lens array 20, 620 could also be formed invarious shapes other than a rectangle so as to conform to a shape of asample well tray.

FIGS. 1-4 show the lens array 20 in combination with a heated cover 30and sample well tray 40 with a plurality of sample wells 44. In certainembodiments, lens array 20, 620 can be used with other sample testingdevices that may or may not have a heated cover. For example, FIG. 7shows the lens array 20 in use with a sample testing device that doesnot have a heated cover.

In FIG. 7, lens array 20 is used in combination with a microcard sampletray 140. As discussed above, microcard sample trays are known to thoseskilled in the art. In the embodiment shown in FIG. 7, microcard sampletray 140 includes a plurality of sample wells or chambers 144 configuredto contain a sample for testing. Chambers 144 may align with a matrix oflenses in a fashion similar to the sample well tray 40 of FIG. 1.Microcard sample tray 140 can have any of the various configurations,sizes and shapes known in the art. In the embodiment shown in FIG. 5,the microcard sample tray is used without a heated cover. Microcardsample tray 140 may also be used with a heated cover.

It should be appreciated that the lens array 20, 620, including the lenssegments 26 with diffractive and/or refractive features are illustrativeonly and are not intended to be drawn to scale.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about.” Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the following specification andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by the present invention. Atthe very least, and not as an attempt to limit the application of thedoctrine of equivalents to the scope of the claims, each numericalparameter should at least be construed in light of the number ofreported significant digits and by applying ordinary roundingtechniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the invention are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contains certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements. Moreover, all ranges disclosed hereinare to be understood to encompass any and all subranges subsumedtherein. For example, a range of “less than 10” includes any and allsubranges between (and including) the minimum value of zero and themaximum value of 10, that is, any and all subranges having a minimumvalue of equal to or greater than zero and a maximum value of equal toor less than 10, e.g., 1 to 5.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the,” include plural referents unlessexpressly and unequivocally limited to one referent. Thus, for example,reference to “a biological” includes two or more different biologicalsamples. As used herein, the term “include” and its grammatical variantsare intended to be non-limiting, such that recitation of items in a listis not to the exclusion of other like items that can be substituted oradded to the listed items.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure. Thus, itshould be understood that the invention is not limited to the examplesdiscussed in the specification. Rather, the present invention isintended to cover modifications and variations.

What is claimed is:
 1. An optical detection system, comprising: a sampleblock assembly configured to receive a plurality of biological samples;a light source configured to illuminate the plurality of biologicalsamples; a light detection device configured to detect luminescence fromat least one of the biological samples; a lens comprising first andsecond surfaces formed thereon, the first surface configured tocollimate light from the light source, the second surface comprising aplurality of optical elements configured to receive transmitted lightfrom the first surface and to illuminate corresponding ones of theplurality of biological samples; and a heated cover configured toreceive the lens.
 2. The optical detection system of claim 1, whereinthe heated cover and the lens are disposed along an optical path betweenthe light source and the sample block assembly, wherein the heated coverand the lens are disposed along an optical path between the sample blockassembly and the light detection device.
 3. The optical detection systemof claim 1, wherein the sample block assembly includes the heated cover.4. The optical detection system of claim 1, wherein the plurality ofoptical elements comprises at least one of a plurality of lenses or aplurality of diffractive elements.
 5. The optical detection system ofclaim 1, wherein each of the optical elements comprises a hybrid surfacecomprising a refractive feature and a diffractive feature.
 6. Theoptical detection system of claim 1, wherein the light source comprisesa light emitting diode.
 7. The optical detection system of claim 1,further comprising a sample holder disposed in or on the sample blockassembly, the sample holder comprising a plurality of sample chambersconfigured to contain corresponding biological samples.
 8. An opticaldetection system, comprising: a sample block assembly configured toreceive a plurality of biological samples; a light source configured toilluminate the plurality of biological samples; a light detection deviceconfigured to detect luminescence from at least one of the biologicalsamples; a lens comprising first and second surfaces formed thereon, thefirst surface configured to collimate light from the light source, thesecond surface comprising a plurality of optical elements configured toreceive transmitted light from the first surface and to illuminatecorresponding ones of the plurality of biological samples; and a heatedcover disposed along an optical path between the light source and thesample block assembly, the heated cover comprising a plurality ofopenings, the openings being tapered from an upper edge of the openingto a lower edge of the opening.
 9. The optical detection system of claim8, wherein the heated cover is configured to receive the lens.
 10. Theoptical detection system of claim 8, wherein the heated cover and thelens are disposed along the optical path between the light source andthe sample block assembly, wherein the heated cover and the lens aredisposed along an optical path between the sample block assembly and thelight detection device.
 11. The optical detection system of claim 8,wherein the sample block assembly includes the heated cover.
 12. Theoptical detection system of claim 8, wherein the plurality of opticalelements comprises at least one of a plurality of lenses or a pluralityof diffractive elements.
 13. The optical detection system of claim 8,wherein each of the optical elements comprises a hybrid surfacecomprising a refractive feature and a diffractive feature.
 14. Theoptical detection system of claim 8, wherein the light source comprisesa light emitting diode.
 15. The optical detection system of claim 8,further comprising a sample holder disposed in or on the sample blockassembly, the sample holder comprising a plurality of sample chambersconfigured to contain corresponding biological samples.